According to a new study published in the journal, Nature Microbiology, while genetic factors influence our metabolism, the food we consume may be also be affecting our genes. The researchers made the discovery in yeast, which is often used as a model organism to study cellular metabolism.
The activity inside each cell is governed by the genetic material housed in the nucleus, along with the cellular processes that make up the cell’s metabolism. Enzymes inside the cell work to synthesize compounds needed for cell growth and division, as well as break down molecules to provide energy.
While the genome contains the information for all of these processes, the DNA itself can be regulated by other DNA sequences, along with epigenetic modifiers. These epigenetic effects can be attributed to the action of small molecules, which interact with the DNA much like an on/off switch.
Previous studies have provided evidence that biochemical reactions that take place as part of the cell’s metabolism, may also play a role in regulating gene expression. As the cell’s metabolism is highly-dependent on the availability of nutrients derived from diet – including sugars, fatty acids, amino acids and vitamins – the expression of certain DNA sequences may also be reliant on these essential factors.
Dr. Markus Ralser, of the University of Cambridge and the Francis Crick Institute in London, and his colleagues set out to determine to what extent the cell’s metabolism affects gene expression. The researchers used yeast in their experiments because it’s easy to grow and manipulate compared to animal models, and its relative genetic similarity to humans.
Ralser and his colleagues controlled the levels of select metabolites within the yeast cells, and studied the behavior of the DNA based on this manipulation. The researchers found that nearly 90 percent of all genes studied were altered by the changes in cellular metabolism.
“Cellular metabolism plays a far more dynamic role in the cells than we previously thought,” said Rasler. “Nearly all of a cell’s genes are influenced by changes to the nutrients they have access to. In fact, in many cases the effects were so strong, that changing a cell’s metabolic profile could make some of its genes behave in a completely different manner.
“The classical view is that genes control how nutrients are broken down into important molecules, but we’ve shown that the opposite is true, too: how the nutrients break down affects how our genes behave.” According to the researchers, the findings may explain why individuals respond differently to certain drugs.
“Another important aspect of our findings is a practical one for scientists,” said Rasler. “Biological experiments are often not reproducible between laboratories and we often blame sloppy researchers for that. It appears however, that small metabolic differences can change the outcomes of the experiments. We need to establish new laboratory procedures that control better for differences in metabolism. This will help us to design better and more reliable experiments.”